Systemd – Drop-In Fails to Create PID File

filespidsystemd

I have a drop-in for systemd-machined at the path /etc/systemd/system/systemd-machined.service.d/10-machined-pid-file.conf. when I run systemctl status systemd-machined I do see the lines

Drop-In: /etc/systemd/system/systemd-machined.service.d
       └─10-machined-pid-file.conf

However, I do not see a PID file in /var/run/. Which based on my drop-in:

[Serivce]
PIDFile=/var/run/machined.pid

I believe there should not be any issue creating that PID file. Is there something I am missing?

Best Answer

The PIDFile= setting does not create a PID file. That is still up to the service itself to do, the same as it has been for the last 40 years. Rather, this option tells systemd where to find an existing PID file (if any). In most cases it's not required at all, as systemd will keep services in their own cgroups and does not need a PID file to keep track of them. However, systemd will delete a PID file when the service exits, if the service fails to clean up after itself.

From the documentation:

Takes an absolute file name pointing to the PID file of this daemon. Use of this option is recommended for services where Type= is set to forking. systemd will read the PID of the main process of the daemon after start-up of the service. systemd will not write to the file configured here, although it will remove the file after the service has shut down if it still exists.

Related Solutions

Centos – sshd running but no PID file

I have the same problem. I fixed it, temporarily at least, by killing the sshd process and then starting it.

    service sshd status
    openssh-daemon is stopped

(even though I am logged in via ssh)

    rpm -vV openssh openssh-server openssh-clients | grep 'S\.5'
    S.5....T  c /etc/ssh/sshd_config

    netstat -anp | grep sshd
    tcp    0      0 0.0.0.0:22           0.0.0.0:*          LISTEN      17501/sshd

    kill 17501
    service sshd start

    service sshd status
    openssh-daemon (pid  3157) is running...

And now monit is happy, too. :)

Ubuntu – Where is systemd script for thesql.service located

For units defined in static files you could use systemctl status, with the information outputed issuing that command, you will be able to see its location.

For example:

# systemctl  status sshd
● sshd.service - OpenSSH Daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2016-10-31 17:01:01 UTC; 1 weeks 0 days ago
 Main PID: 283 (sshd)
    Tasks: 1 (limit: 4915)
   CGroup: /system.slice/sshd.service
           └─290 /usr/bin/sshd -D

Note that the tab command could be helpful here.

Therefore, in my system the systemd services are placed under /usr/lib/systemd/. Please, note that there could be folders in that location.

Another way is to use the find command in that specific location to find a service:

# find /usr/lib/systemd/ | grep -i mysql

I hope that helps ;)

Best Answer

Related Solutions

Centos – sshd running but no PID file

Ubuntu – Where is systemd script for thesql.service located

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